Stone and metal conglomerate eoe paving



GEO. H. KNIGHT, or CINCINNATI, oHIo.

`STONE AND METAL CONGLOMERATE Een PAVING, sac,

"Specification of Letters Patent No. 8,020, dated April 1, 1851.

To all 'whom t may concern.:

Be it known that I, GEORGE H. KNIGHT, of Cincinnati, Hamilton county, Ohio, have invented a new and Improved' Method of Constructing Blocks for Pavements, Tread-` ways, and Analogous Purposes;` and I do hereby declare the` following to be a full, clear, and exact description thereof, reference` being had to `the annexed drawings, making part of this specification. j

The nature of my invention consists in `the formation of a conglomerate block composed of stone and iron, by pouring the molten metal around and amongbroken stone with-` in a mold, the metal forming a bond of union by which the stone is held together in one coherent mass, and so distributed among the metal as t`o present a. nearly uniform mixture of the two materials in such proportion as may be desired.

With regard to pavements, the proposed system when compared to the best granite pavement, (besides dispensing altogether with the labor and skill of dressing) admits of a diminution of bulk, because of the greater Acohesive strength of the iron, the

. depth necessary for the conglomerate blockeallowing for wear-being from four to six inches, -instead of from ten to fourteen inches depth, usual in good granite pavement, and this diminution in depth decreases the cost of transportation, and by the greater portability, expedites the laying down of the pavement, and from the same cause, a con-v glomerate block may without being unwieldy be made to extend over a broader area than a granite block, and consequently be less liable to sink unequally beneath heavy loads, and thus the most frequent cause of repair-the yielding. of the foundationmay be avoided, and the foundation itself being subjected to less trying dut-y, may be less costly in its character, and while on the one hand, a greater regularity of the general surface will be admissible, there will at the same time-from the diversity of the material-permanently remain numerous minute irregularities insuring firm foothold for the horses hoof. There is no particular skill or tedious labor required-the stonemaso-ns chisel is exchanged for the stone sents in outline perspective a roadway paved with conglomerateblocks. `Figs. 2, 3 and 4 show more particularly .a number of de-` tached blocks having alternately grooves (a) and lugs by which each individual course h of blocks may be interlocked with :its neigh` bors.

` By these devices the pressure may be dis` tributed from each particular stone to those aroundiit and a stability may thereby be attained which may be very serviceable in the main thoroughfares of cities. This feature is however only adverted to here as an advantage incidental to but not necessarily involvedin the main invention. i

I `This invention may also be applied with advantage to the treadways of mills, ferryboats vor. horse powers, to the walls and arches of tunnels, to light-houses, breakwaters and other structures subject to great strain-and also to masonry in general, blocks of this construction having greater strength and involving far less skill and labor to shape them than blocks of dressed stone or marble.

It is advisable to heat the stoneprevious to its insertion into the mold, especially where the pieces are large; this not only dissipates any moisture hanging about them,

but prevents the splintering of their sub- I stance by the sudden expansion of their exterior upon the contact of the hot metal. p

It has been also found advisable `where the block is'a large one tointroduce the metal at several points simultaneously. By filling the interstices of one dimension of stones with others of a smaller size a very large portion of the entire mass may be nonmetallic.

Having thus described the nature of my invention what I claim therein as new and for which I desire Letters Patent is Forming a block suitable for paving, masonrywork or analogous purposes, of a conglomerate of iron and stone, by running the molten-metal among broken stone within a 

